/*
 * Copyright (C) 2005-2011 MaNGOS <http://www.getmangos.com/>
 *
 * Copyright (C) 2008-2011 Trinity <http://www.trinitycore.org/>
 *
 * Copyright (C) 2010-2011 ArkCORE <http://www.arkania.net/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#ifndef ARKCORE_UNITAI_H
#define ARKCORE_UNITAI_H

#include "Define.h"
#include <list>
#include "Unit.h"

class Unit;
class Player;
struct AISpellInfoType;

// Default script texts
enum GeneralScriptTexts {
	DEFAULT_TEXT = -1000000,
	EMOTE_GENERIC_FRENZY_KILL = -1000001,
	EMOTE_GENERIC_FRENZY = -1000002,
	EMOTE_GENERIC_ENRAGED = -1000003,
	EMOTE_GENERIC_BERSERK = -1000004,
	EMOTE_GENERIC_BERSERK_RAID = -1000005,
// RaidBossEmote version of the previous one
};

//Selection method used by SelectTarget
enum SelectAggroTarget {
	SELECT_TARGET_RANDOM = 0, //Just selects a random target
	SELECT_TARGET_TOPAGGRO, //Selects targes from top aggro to bottom
	SELECT_TARGET_BOTTOMAGGRO, //Selects targets from bottom aggro to top
	SELECT_TARGET_NEAREST,
	SELECT_TARGET_FARTHEST,
};

// default predicate function to select target based on distance, player and/or aura criteria
struct DefaultTargetSelector: public std::unary_function<Unit *, bool> {
	const Unit *me;
	float m_dist;
	bool m_playerOnly;
	int32 m_aura;

	// pUnit: the reference unit
	// dist: if 0: ignored, if > 0: maximum distance to the reference unit, if < 0: minimum distance to the reference unit
	// playerOnly: self explaining
	// aura: if 0: ignored, if > 0: the target shall have the aura, if < 0, the target shall NOT have the aura
	DefaultTargetSelector(const Unit *pUnit, float dist, bool playerOnly,
			int32 aura) :
			me(pUnit), m_dist(dist), m_playerOnly(playerOnly), m_aura(aura) {
	}

	bool operator()(const Unit *pTarget) {
		if (!me)
			return false;

		if (!pTarget)
			return false;

		if (m_playerOnly && (pTarget->GetTypeId() != TYPEID_PLAYER))
			return false;

		if (m_dist > 0.0f && !me->IsWithinCombatRange(pTarget, m_dist))
			return false;

		if (m_dist < 0.0f && me->IsWithinCombatRange(pTarget, -m_dist))
			return false;

		if (m_aura) {
			if (m_aura > 0) {
				if (!pTarget->HasAura(m_aura))
					return false;
			} else {
				if (pTarget->HasAura(-m_aura))
					return false;
			}
		}

		return true;
	}
};

// Very simple target selector, will just skip main target
// NOTE: When passing to UnitAI::SelectTarget remember to use 0 as position for random selection
//       because tank will not be in the temporary list
struct NonTankTargetSelector : public std::unary_function<Unit*, bool>
{
    public:
        NonTankTargetSelector(Creature* source, bool playerOnly = true) : _source(source), _playerOnly(playerOnly) { }
        bool operator()(Unit const* target) const;

    private:
        Creature const* _source;
        bool _playerOnly;
};

class UnitAI {
protected:
	Unit * const me;
public:
	explicit UnitAI(Unit *u) :
			me(u) {
	}
	virtual ~UnitAI() {
	}

	virtual bool CanAIAttack(const Unit * /*who*/) const {
		return true;
	}
	virtual void AttackStart(Unit *);
	virtual void UpdateAI(const uint32 diff) = 0;

	virtual void InitializeAI() {
		if (!me->isDead())
			Reset();
	}

	virtual void Reset() {
	}
	;

	// Called when unit is charmed
	virtual void OnCharmed(bool apply) = 0;

	// Pass parameters between AI
	virtual void DoAction(const int32 /*param*/= 0) {
	}
	virtual uint32 GetData(uint32 /*id = 0*/) {
		return 0;
	}
	virtual void SetData(uint32 /*id*/, uint32 /*value*/) {
	}
	virtual void SetGUID(const uint64 &/*guid*/, int32 /*id*/= 0) {
	}
	virtual uint64 GetGUID(int32 /*id*/= 0) {
		return 0;
	}

	Unit* SelectTarget(SelectAggroTarget targetType, uint32 position = 0,
			float dist = 0.0f, bool playerOnly = false, int32 aura = 0);
	void SelectTargetList(std::list<Unit*> &targetList, uint32 num,
			SelectAggroTarget targetType, float dist = 0.0f, bool playerOnly =
					false, int32 aura = 0);

	// Called at any Damage to any victim (before damage apply)
	virtual void DamageDealt(Unit* /*victim*/, uint32& /*damage*/,
			DamageEffectType /*damageType*/) {
	}

	// Called at any Damage from any attacker (before damage apply)
	// Note: it for recalculation damage or special reaction at damage
	// for attack reaction use AttackedBy called for not DOT damage in Unit::DealDamage also
	virtual void DamageTaken(Unit* /*attacker*/, uint32& /*damage*/) {
	}

	// Called when the creature receives heal
	virtual void HealReceived(Unit* /*done_by*/, uint32& /*addhealth*/) {
	}

	// Called when the unit heals
	virtual void HealDone(Unit* /*done_to*/, uint32& /*addhealth*/) {
	}

	// Select the targets satifying the predicate.
	// predicate shall extend std::unary_function<Unit *, bool>
	template<class PREDICATE> Unit* SelectTarget(SelectAggroTarget targetType,
			uint32 position, PREDICATE predicate) {
		const std::list<HostileReference *> &threatlist =
				me->getThreatManager().getThreatList();
		std::list<Unit*> targetList;

		if (position >= threatlist.size())
			return NULL;

		for (std::list<HostileReference*>::const_iterator itr =
				threatlist.begin(); itr != threatlist.end(); ++itr) {
			HostileReference* ref = (*itr);
			if (predicate(ref->getTarget()))
				targetList.push_back(ref->getTarget());
		}

		if (position >= targetList.size())
			return NULL;

		if (targetType == SELECT_TARGET_NEAREST
				|| targetType == SELECT_TARGET_FARTHEST)
			targetList.sort(Trinity::ObjectDistanceOrderPred(me));

		switch (targetType) {
		case SELECT_TARGET_NEAREST:
		case SELECT_TARGET_TOPAGGRO: {
			std::list<Unit*>::iterator itr = targetList.begin();
			advance(itr, position);
			return *itr;
		}
			break;

		case SELECT_TARGET_FARTHEST:
		case SELECT_TARGET_BOTTOMAGGRO: {
			std::list<Unit*>::reverse_iterator ritr = targetList.rbegin();
			advance(ritr, position);
			return *ritr;
		}
			break;

		case SELECT_TARGET_RANDOM: {
			std::list<Unit*>::iterator itr = targetList.begin();
			advance(itr, urand(position, targetList.size() - 1));
			return *itr;
		}
			break;
		}

		return NULL;
	}

	void AttackStartCaster(Unit *victim, float dist);

	void DoAddAuraToAllHostilePlayers(uint32 spellid);
	void DoCast(uint32 spellId);
	void DoCast(Unit* victim, uint32 spellId, bool triggered = false);
	void DoCastToAllHostilePlayers(uint32 spellid, bool triggered = false);
	void DoCastVictim(uint32 spellId, bool triggered = false);
	void DoCastAOE(uint32 spellId, bool triggered = false);

	float DoGetSpellMaxRange(uint32 spellId, bool positive = false);

	void DoMeleeAttackIfReady();
	bool DoSpellAttackIfReady(uint32 spell);

	static AISpellInfoType *AISpellInfo;
	static void FillAISpellInfo();

	virtual void sGossipHello(Player* /*player*/) {
	}
	virtual void sGossipSelect(Player* /*player*/, uint32 /*sender*/,
			uint32 /*action*/) {
	}
	virtual void sGossipSelectCode(Player* /*player*/, uint32 /*sender*/,
			uint32 /*action*/, const char* /*code*/) {
	}
	virtual void sQuestAccept(Player* /*player*/, Quest const* /*quest*/) {
	}
	virtual void sQuestSelect(Player* /*player*/, Quest const* /*quest*/) {
	}
	virtual void sQuestComplete(Player* /*player*/, Quest const* /*quest*/) {
	}
	virtual void sQuestReward(Player* /*player*/, Quest const* /*quest*/,
			uint32 /*opt*/) {
	}
	virtual bool sOnDummyEffect(Unit* /*caster*/, uint32 /*spellId*/,
			SpellEffIndex /*effIndex*/) {
		return false;
	}
};

class PlayerAI: public UnitAI {
protected:
	Player* const me;
public:
	explicit PlayerAI(Player *p) :
			UnitAI((Unit*) p), me(p) {
	}

	void OnCharmed(bool apply);
};

class SimpleCharmedAI: public PlayerAI {
public:
	void UpdateAI(const uint32 diff);
	SimpleCharmedAI(Player *p) :
			PlayerAI(p) {
	}
};

#endif
